Distinguishing two single-mode Gaussian states by homodyne detection: An information-theoretic approach Academic Article uri icon


  • It is known that quantum fidelity, as a measure of the closeness of two quantum states, is operationally equivalent to the minimal overlap of the probability distributions of the two states over all possible positive-operator-valued measures (POVM's); the POVM realizing the minimum is optimal. We consider the ability of homodyne detection to distinguish two single-mode Gaussian states and investigate to what extent it is optimal in this information-theoretic sense. We completely identify the conditions under which homodyne detection makes an optimal distinction between two single-mode Gaussian states of the same mean and show that, if the Gaussian states are pure, they are always optimally distinguished. © 2005 The American Physical Society.

published proceedings

  • Physical Review A

author list (cited authors)

  • Nha, H., & Carmichael, H. J

citation count

  • 27

complete list of authors

  • Nha, Hyunchul||Carmichael, HJ

publication date

  • March 2005